Drupal 6: Programatically add a user to an organic group when they register

I am working on an invitation system using organic groups and I needed the ability to programatically add a user to a (closed) organic group when they register for a new account. I tried to use the og_subscribe_user function, but it tests if the group allows registrations. In my situation the groups are closed, so I had to resort to the og_save_subscription function:

<?phpfunctionMYMODULE_user($op,&$edit,&$account,$category=NULL){switch($op){case'insert':// in my example, I'm querying a database for this number:$groupID='some number';og_save_subscription($groupID,$account->uid,array('is_active'=>1));break;}}?>